Non-enhanced ECG-gated respiratory-triggered 3-D steady-state free-precession MR angiography with slab-selective inversion: initial experience in visualisation of renal arteries in free-breathing children without renal artery abnormality

Background

ECG-gated non-enhanced balanced steady-state free precession (bSSFP) MR angiography requires neither breath-holding nor administration of contrast material.

Objective

To investigate the image quality of free-breathing ECG-gated non-enhanced bSSFP MR angiography of renal arteries in children.

Materials and methods

Fourteen boys and seven girls (mean age, 9.7?years; range, 7?weeks–17?years) with no history of renovascular disease were included. MRI was performed at 1.5?T. Subjective image quality of axial and coronal maximum-intensity-projection reconstructions of four segments (I, aorta and renal artery ostium; II, main renal artery; III, segmental branches; IV, intrarenal vessels) was evaluated using a 4-point scale (4?=?excellent, 3?=?good, 2?=?acceptable, 1?=?non-diagnostic).

Results

Image quality was excellent for segments I (mean ± SD, 3.9?±?0.3) and II (4.0?±?0.1), good for segment III (3.4?±?0.9) and acceptable for segment IV (2.3?±?1.1 ). Mean image quality did not differ between sedated and non-sedated children.

Conclusion

bSSFP MR angiography enables visualisation of renal arteries in children.     

Evaluation of the impact of organ-specific dose reduction on image quality in pediatric chest computed tomography

Background

Organ-specific dose reduction significantly reduces the radiation exposure of radiosensitive organs.

Objective

The purpose of this study was to assess the impact of a novel organ-specific dose reduction algorithm on image quality of pediatric chest CT.

Materials and methods

We included 28 children (mean age 10.9?±?4.8 years, range 3–18 years) who had contrast-enhanced chest CT on a 128-row scanner. CT was performed at 100 kV using automated tube current modulation and a novel organ-specific dose-reduction algorithm (XCare?; Siemens, Forchheim, Germany). Seven children had a previous chest CT performed on a 64-row scanner at 100 kV without organ-specific dose reduction. Subjective image quality was assessed using a five-point scale (1-not diagnostic; 5-excellent). Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were assessed in the descending aorta.

Results

Overall mean subjective image quality was 4.1?±?0.6. In the subgroup of the seven children examined both with and without organ-specific dose reduction, subjective image quality was comparable (score 4.4?±?0.5 with organ-specific dose reduction vs. 4.4?±?0.7 without it; P?>?0.05). There was no significant difference in mean signal-to-noise ratio and contrast-to-noise ratio with organ-specific dose reduction (38.3?±?10.1 and 28.5?±?8.7, respectively) and without the reduction (35.5?±?8.5 and 26.5?±?7.8, respectively) (P?>?0.05). Volume computed tomography dose index (CTDI_vol) and size-specific dose estimates did not differ significantly between acquisitions with the organ-specific dose reduction (1.7?±?0.8 mGy) and without the reduction (1.7?±?0.8 mGy) (P?>?0.05).

Conclusion

Organ-specific dose reduction does not have an impact on image quality of pediatric chest CT and can therefore be used in clinical practice to reduce radiation dose of radiosensitive organs such as breast and thyroid gland.     

Evaluation of image quality and radiation dose at prospective ECG-triggered axial 256-slice multi-detector CT in infants with congenital heart disease

Background

There are a limited number of reports on the technical and clinical feasibility of prospective electrocardiogram (ECG)-gated multi-detector computed tomography (MDCT) in infants with congenital heart disease (CHD).

Objective

To evaluate image quality and radiation dose at weight-based low-dose prospectively gated 256-slice MDCT angiography in infants with CHD.

Materials and methods

From November 2009 to February 2010, 64 consecutive infants with CHD referred for pre-operative or post-operative CT were included. All were scanned on a 256-slice MDCT system utilizing a low-dose protocol (80?kVp and 60?C120?mAs depending on weight: 60?mAs for ??3?kg, 80?mAs for 3.1?C6?kg, 100?mAs for 6.1?C10?kg, 120?mAs for 10.1?C15?kg).

Results

No serious adverse events were recorded. A total of 174 cardiac deformities, confirmed by surgery or heart catheterization, were studied. The sensitivity of MDCT for cardiac deformities was 97.1%; specificity, 99.4%; accuracy, 95.9%. The mean heart rate during scan was 136.7?±?14.9/min (range, 91?C160) with a corresponding heart rate variability of 2.8?±?2.2/min (range, 0?C8). Mean scan length was 115.3?±?11.7?mm (range, 93.6?C143.3). Mean volume CT dose index, mean dose-length product and effective dose were 2.1?±?0.4?mGy (range, 1.5?C2.8), 24.7?±?5.9?mGy·cm (range, 14.7?C35.8) and 1.6?±?0.3?mSv (range, 1.1?C2.5), respectively. Diagnostic-quality images were achieved in all cases. Satisfactory diagnostic quality for visualization of all/proximal/distal coronary artery segments was achieved in 88.4/98.8/80.0% of the scans.

Conclusion

Low-dose prospectively gated axial 256-slice CT angiography is a valuable tool in the routine clinical evaluation of infants with CHD, providing a comprehensive three-dimensional evaluation of the cardiac anatomy, including the coronary arteries.     

Individualized volume CT dose index determined by cross-sectional area and mean density of the body to achieve uniform image noise of contrast-enhanced pediatric chest CT obtained at variable kV levels and with combined tube current modulation

Background

A practical body-size adaptive protocol providing uniform image noise at various kV levels is not available for pediatric CT.

Objective

To develop a practical contrast-enhanced pediatric chest CT protocol providing uniform image noise by using an individualized volume CT dose index (CTDIvol) determined by the cross-sectional area and density of the body at variable kV levels and with combined tube current modulation.

Materials and methods

A total of 137 patients (mean age, 7.6?years) underwent contrast-enhanced pediatric chest CT based on body weight. From the CTDIvol, image noise, and area and mean density of the cross-section at the lung base in the weight-based group, the best fit equation was estimated with a very high correlation coefficient (??²?=?0.86, P?Results The CTDIvol values (mean±standard deviation, 1.6?±?0.7?mGy) and the noise differences from the target noise (1.1?±?0.9?HU) of the CTDIvol group were significantly lower than those of the weight-based group (2.0?±?1.0?mGy, 1.8?±?1.4?HU) (P?2 vs. 326.3?±?124.8 cm²), mean density (?212.9?±?53.1?HU vs. ?221.1?±?56.3?HU), and image noise (13.8?±?2.3 vs. 13.6?±?1.7?HU) between the weight-based and the CTDIvol groups (P?>?0.05).

Conclusion

Contrast-enhanced pediatric chest CT with the CTDIvol determined individually by the cross-sectional area and density of the body provides more uniform noise and better dose adaptation to body habitus than does weight-based CT at variable kV levels and with combined tube current modulation.     

Detection of pulmonary nodules at paediatric CT: maximum intensity projections and axial source images are complementary

Background

Maximum intensity projection (MIP) images might be useful in helping to differentiate small pulmonary nodules from adjacent vessels on thoracic multidetector CT (MDCT).

Objective

The aim was to evaluate the benefits of axial MIP images over axial source images for the paediatric chest in an interobserver variability study.

Materials and methods

We included 46 children with extra-pulmonary solid organ malignancy who had undergone thoracic MDCT. Three radiologists independently read 2-mm axial and 10-mm MIP image datasets, recording the number of nodules, size and location, overall time taken and confidence.

Results

There were 83 nodules (249 total reads among three readers) in 46 children (mean age 10.4?±?4.98 years, range 0.3–15.9 years; 24 boys). Consensus read was used as the reference standard. Overall, three readers recorded significantly more nodules on MIP images (228 vs. 174; P < 0.05), improving sensitivity from 67% to 77.5% (P < 0.05) but with lower positive predictive value (96% vs. 85%, P < 0.005). MIP images took significantly less time to read (71.6?±?43.7 s vs. 92.9?±?48.7 s; P < 0.005) but did not improve confidence levels.

Conclusion

Using 10-mm axial MIP images for nodule detection in the paediatric chest enhances diagnostic performance, improving sensitivity and reducing reading time when compared with conventional axial thin-slice images. Axial MIP and axial source images are complementary in thoracic nodule detection.     

Evaluation of carotid intima-media thickness, a marker of subclinical atherosclerosis, in children with cerebral palsy

Background

Respiratory and cardiovascular diseases are the most common causes of death in children with cerebral palsy.

Objective

To evaluate sonographic carotid intima-media thickness, an early marker of atherosclerosis, in children with cerebral palsy and in healthy controls.

Materials and methods

One hundred children with cerebral palsy (65 boys), mean age 6.2 (SD, 2.1) years, and 35 age-matched and sex-matched healthy controls were included. Common carotid artery intima-media thickness was measured sonographically. Differences between patients and controls were evaluated with an independent samples t-test.

Results

Age, sex distribution and levels of serum lipids were comparable between patients and controls. Average, right and left carotid artery intima-media were thicker in patients compared with controls (mean ± SD, 0.61?±?0.13 mm vs 0.40?±?0.03 mm; 0.61?±?0.14 mm vs 0.40?±?0.03 mm; 0.61?±?0.13 mm vs 0.40?±?0.03 mm, respectively; all P?Conclusion Carotid intima-media is sonographically thicker in children with cerebral palsy compared with healthy controls, which may express an increased risk of atherosclerotic diseases.     

Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation

Background

Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis.

Objective

To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard.

Materials and methods

The study group comprised 12 patients (age 17.6?±?2.9?years, mean±SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6?±?13.5?months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA.

Results

Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56?±?0.95?mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n?=?32), stenoses (n?=?3) and occlusions (n?=?9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention.

Conclusion

Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures.     

A modified laparoscopic splenectomy for massive splenomegaly in children with hematological disorder: a single institute retrospective clinical research

Purpose

With the optimal acceptance of its clinical advantages, laparoscopic splenectomy (LS) emerged as a gold standard procedure as compared with open splenectomy (OS). However, it is still controversial and even counted as contraindication for massive splenomegaly. Here, we aim to summarize the experiences, characteristics and trends of modified LS for massive splenomegaly in children with hematological disorders.

Methods

Retrospective series of 57 pediatric patients with massive splenomegaly who underwent splenectomy from March 2007 to December 2011 were designated for this clinical analysis. The main outcome measures were dealt by statistics. For 30 cases of LS, we strictly adhered to the principle of using only three trocars to operate and initial ligation of the splenic artery, followed by retrieving the piecemeal of spleen through an accessory incision of 2?C3?cm at 12?mm trocar port site.

Results

Of the 57 pediatric patients, 27 underwent OS and 30 underwent LS, respectively. Despite the operative time being shorter for OS than for LS (P?<?0.001), the blood loss was lower in LS than in OS (P?<?0.001); the time required for oral intake as well as duration of hospital stay was lower in LS than in OS (P?<?0.001). Post-operatively, 7 (25.9?%) complications occurred in OS and 3 (10?%) in LS. The conversion rate of LS to OS was 13.33?% in four cases till 2009.

Conclusions

Despite the conflicting reports regarding the safety of LS for massive splenomegaly, we demonstrated that our modified laparoscopic splenectomy in the treatment of children with massive splenomegaly in hematological diseases seemed to achieve the fundamental goal of less invasion; it was safe and feasible.     

Pediatric chest CT at 70 kVp: a feasibility study in 129 children

Background

Before introducing 70-kVp settings in the low-kilovoltage strategies for pediatric examinations, it was mandatory to demonstrate, at similar dose levels, an equivalence of image quality at 70 kVp and 80 kVp.

Objective

To assess image quality of chest CT examinations acquired at 70 kVp in comparison with standard scanning at 80 kVp.

Materials and methods

We prospectively evaluated 129 children with a 70-kVp scanning protocol (group 1). All scanning parameters were kept similar to those usually selected for pediatric standard 80-kVp protocols, except the milliamperage increased by a factor of 1.6 to maintain comparable radiation dose. Image quality of group 1 examinations was compared to that of a paired population scanned at 80 kVp (group 2). The noninferiority hypothesis was fixed at 10% of the mean level of image noise.

Results

There was no significant difference in the mean dose length product (DLP) and the volume computed tomography dose index (CTDI_vol) between the groups (DLP: 20.5?±?5.8 mGy.cm [group 1] vs. 19.7?±?7.6 mGy.cm [group 2]; P?=?0.06) (CTDI_vol: 0.8?±?0.1 mGy [group 1] vs. 0.8?±?0.18 mGy [group 2]; P?=?0.94). The mean of differences in image noise between group 1 and group 2 examinations was ?1.38 (?2.59; ?0.18), verifying the noninferiority hypothesis. Subjective image quality did not significantly differ between group 1 and group 2 examinations (P?=?0.18).

Conclusion

At equivalent radiation dose levels, 70-kVp protocols provide similar image quality to that achievable at 80 kVp.     

Pulmonary function and exercise capacity in children following lung resection surgery

Purpose

To study lung function and exercise capacity in children following lung resection surgery.

Methods

Children aged 6?C18?years who had lung resection surgery were studied and compared to normal children (age and sex matched). All had spirometry/body plethysmography and exercise stress test (performed by treadmill and modified Balke protocol).

Results

13 Patients and 13 controls were studied (age 13.2?±?3.3?years; 46.2?% male). The age at the time of lung resection surgery was 6.5?±?4.7?years. The time interval between post-surgery and the tests was 6.8?±?4.4?years. The most common indication for lung resection surgery was congenital lung malformations (61.5?%). 76.9?% of the patients had abnormal lung function. Exercise intolerance due to pulmonary limitations was found in 23.1?% of the patients. At the anaerobic threshold, the $ V_{{{\text{O}}_{2} }} /{\text{kg}} $ was not different between the patients and the controls. However, at the end of the exercise, the patients demonstrated lower peak $ V_{{{\text{O}}_{2} }} /{\text{kg}} $ than the controls (33.6?±?6.0 vs. 39.3?±?8.7?ml/min/kg; p?<?0.01).

Conclusions

Abnormal lung functions and exercise intolerance were found in children following lung resection surgery. Children who had lung resection surgery had lower exercise capacity than normal children if the exercise was beyond the anaerobic threshold.     

Effect of physical activity and sun exposure on vitamin D status of Saudi children and adolescents

Background

1) To evaluate calcium absorption in infants fed a formula containing prebiotics (PF) and one without prebiotics (CF). 2) To compare calcium absorption from these formulas with a group of human milk-fed (HM) infants.

Methods

A dual tracer stable isotope method was used to assess calcium absorption in infants exclusively fed CF (n?=?30), PF (n?=?25) or HM (n?=?19). Analysis of variance was used to analyze calcium intake, fractional calcium absorption, and the amount of calcium absorbed.

Results

Calcium intake (Mean ± SEM) for PF was 534?±?17?mg/d and 557?±?16?mg/d for CF (p?=?0.33). Fractional calcium absorption was 56.8?±?2.6?% for PF and 59.2?±?2.3?% for CF (p?=?0.49). Total calcium absorbed for PF was 300?±?14?mg/d and 328?±?13?mg/d for CF (p?=?0.16). For HM infants calcium intake was 246?±?20?mg/d, fractional calcium absorption was 76.0?±?2.9?% and total calcium absorbed was 187?±?16?mg/d (p <0.001, compared to either PF or CF).

Conclusions

Despite lower fractional calcium absorption of CF and PF compared to HM, higher calcium content in both led to higher total calcium absorption compared to HM infants. No significant effect of prebiotics was observed on calcium absorption or other markers of bone mineral metabolism.     

Evaluation of knowledge-based reconstruction for magnetic resonance volumetry of the right ventricle in tetralogy of Fallot

Background

Cardiac magnetic resonance using the Simpson method is the gold standard for right ventricular volumetry. However, this method is time-consuming and not without sources of error. Knowledge-based reconstruction is a novel post-processing approach that reconstructs the right ventricular endocardial shape based on anatomical landmarks and a database of various right ventricular configurations.

Objective

To assess the feasibility, accuracy and labor intensity of knowledge-based reconstruction in repaired tetralogy of Fallot (TOF).

Materials and methods

The short-axis cine cardiac MR datasets of 35 children and young adults (mean age 14.4?±?2.5 years) after TOF repair were studied using both knowledge-based reconstruction and the Simpson method. Intraobserver, interobserver and inter-method variability were assessed using Bland-Altman analyses.

Results

Knowledge-based reconstruction was feasible and highly accurate as compared to the Simpson method. Intra- and inter-method variability for knowledge-based reconstruction measurements showed good agreement. Volumetric assessment using knowledge-based reconstruction was faster when compared with the Simpson method (10.9?±?2.0 vs. 7.1?±?2.4 min, P?Conclusion In patients with repaired tetralogy of Fallot, knowledge-based reconstruction is a feasible, accurate and reproducible method for measuring right ventricular volumes and ejection fraction. The post-processing time of right ventricular volumetry using knowledge-based reconstruction was significantly shorter when compared with the routine Simpson method.     

Topiramate and Propranolol for Prophylaxis of Migraine

Objective

To compare efficacy and safety of topiramate (TPM) and propranolol for migraine prophylaxis in children.

Methods

In a parallel single-blinded randomized clinical trial, 5–15 y-old referred migraineurs to Pediatric Neurology Clinic of Shahid Sadoughi Medical Sciences University, Yazd, Iran from May through October 2011, were evaluated. Patients were distributed into two groups, 50 of whom were treated with 3 mg/kg/d of topiramate (TPM) and another group of 50, were treated with 1 mg/kg of propranolol for 3 mo. Primary endpoints were efficacy in reduction of monthly frequency, severity, duration and headache related disability. Secondary outcome was clinical side effects.

Results

Fifty two girls and 48 boys with mean age of 10.34?±?2.31 y were evaluated. Monthly frequency, severity and duration of headache decreased with TPM, from 13.88?±?8.4 to 4.13?±?2.26 attacks, from 6.32?±?1.93 to 2.8?±?2.12, and from 2.36?±?1.72 to 0.56?±?0.5 h, respectively. Monthly frequency, severity and duration of headache also decreased with propranolol from 16.2?±?6.74 to 8.8?±?4.55 attacks, from 6.1?±?1.54 to 4.8?±?1.6 and from 2.26?±?1.26 to 1.35?±?1.08 h, respectively. Pediatric Migraine Disability Assessment score reduced from 31.88?±?9.72 to 9.26?±?7.21 with TPM and from 33.08?±?8.98 to 23.64?±?9.88 with propranolol. Transient mild side effects were seen in 18 % of TPM and in 10 % of propranolol (P?=?0.249) groups.

Conclusions

Topiramate is more effective than propranolol for pediatric migraine prophylaxis.     

Does Mesenchymal Stem Cell Population in Umbilical Cord Blood Vary at Different Gestational Periods?

Objective

To identify and quantitatively determine Mesenchymal stem cells (MSCs) in the umbilical cord blood (UCB) of neonates born at different gestational periods.

Methods

UCB was collected at birth in neonates of three different gestational groups. The mononuclear cells (MNCs) were phenotypically analyzed by flow cytometer.

Results

The yield of total MNCs did not differ much with gestation; the average values were 22.6?±?6.48?×?106 cells/ml. The MSCs were significantly higher in the lower gestation group. These were 0.0219?±?0.012 %, 0.0044?±?0.003 % and 0.0022?±?0.003 % in 28 to 31 wk, 32 to 35 wk and >36 wk, respectively (P?=?0.00). There was a significant inverse correlation between the gestational age and the presence of MSCs with a correlation co-efficient of ?0.54 (P?=?0.0001).

Conclusions

The MSCs population was significantly higher in infants born at lesser gestation than those born at term gestation.     

Strain measurement by cardiovascular magnetic resonance in pediatric cancer survivors: validation of feature tracking against harmonic phase imaging

Background

Left ventricular strain may be a more sensitive marker of left ventricular dysfunction than ejection fraction in pediatric cancer survivors after anthracycline therapy, but there is limited validation of strain measurement by feature tracking on cardiovascular magnetic resonance (MR) images.

Objective

To compare left ventricular circumferential and radial strain by feature tracking vs. harmonic phase imaging analysis (HARP) in pediatric cancer survivors.

Materials and methods

Twenty-six patients (20.2?±?5.6 years old) underwent cardiovascular MR at least 5 years after completing anthracycline therapy. Circumferential and radial strain were measured at the base, midventricle and apex from short-axis myocardial tagged images by HARP, and from steady-state free precession images by feature tracking.

Results

Left ventricular ejection fraction more closely correlated with global circumferential strain by feature tracking (r?=??0.63, P?=?0.0005) than by HARP (r?=??0.39, P?=?0.05). Midventricular circumferential strain did not significantly differ by feature tracking or HARP (?20.8?±?3.4 vs. ?19.5?±?2.5, P?=?0.07), with acceptable limits of agreement. Midventricular circumferential strain by feature tracking strongly correlated with global circumferential strain by feature tracking (r?=?0.87, P?HARP, particularly at higher values of radial strain. Intraobserver and interobserver reproducibility was excellent for feature tracking circumferential strain, but reproducibility was poor for feature tracking radial strain.

Conclusion

Midventricular circumferential strain by feature tracking is a reliable and reproducible measure of myocardial deformation in patients status post anthracycline therapy, while radial strain measurements are unreliable. Further studies are necessary to evaluate potential relation to long-term outcomes.     

Increasing the accuracy of lung perfusion scintigraphy in children with bidirectional Glenn circulation

Background

In children who have undergone a bidirectional Glenn procedure without antegrade or additional pulmonary blood flow, we have often noted a discrepancy between apparent lung perfusion on scintigraphy and superior vena cava angiography when evaluating right and left pulmonary blood flow. We found a tendency for radionuclide, tracer 99mTc-MAA, when administered through a single upper extremity vein, to preferentially accumulate in the ipsilateral lung.

Objective

In the present study, we examined whether the ratio of right-to-left pulmonary flow varied when 99mTc-MAA was administered via either the right upper or the left upper extremity vein.

Materials and methods

We studied six children (median age 1.3?±?0.23 years) who underwent a bidirectional Glenn before total cavopulmonary connection. Five children who underwent biventricular repair served as a control. Perfusion scintigraphy using 99mTc-labeled macroaggregated albumin (99mTc-MAA) was performed in all children. First, we injected radionuclide via the right upper extremity and calculated the pulmonary accumulation in both lungs (R-image). Second, we injected the same dose of radionuclide via the left upper extremity and calculated the pulmonary accumulation (B-image), which represented the resulting administration via both upper extremities. The lung accumulation that resulted from radionuclide administration via the left upper extremity (L-image) was determined by subtracting the R-image from the B-image. We evaluated the right-to-total pulmonary blood flow ratio (radionuclide accumulation in right lung / radionuclide accumulation in both lungs) in the R-, L- and B-images.

Results

The right-to-total pulmonary blood flow ratios in the R-, L- and B-images were 815?±?15.3%, 39.8?±?11.7% and 61.3?±?11.8%, respectively, and there were significant differences among the three images (P?<?0.01). On the other hand, in the control group, the right-to-total pulmonary blood flow ratios in the R-, L- and B-images were 59.3?±?22.4%, 57.8?±?26.4% and 58.8?±?23.7%, respectively, and there was no significant difference.

Conclusion

In children with bidirectional Glenn circulation without antegrade or additional pulmonary blood flow, the venous blood of each arm tends to flow into the ipsilateral lung. The administration of radionuclide via both arms is important for accurate evaluation of lung perfusion scintigraphy in children who have undergone a bidirectional Glenn procedure.     

Usefulness of Pulsed Wave Tissue Doppler Imaging in Assessment of Left Ventricular Functions in Children with Beta-Thalassemia Major

Objective

To evaluate the changes in the LV systolic and diastolic function in children with beta-thalassemia major (β-TM) using pulsed wave tissue doppler (TD) echocardiography.

Methods

Clinical, conventional echo doppler and pulsed wave tissue doppler imaging parameters were compared in 40 beta-thalassemia major patients (mean age, 6.52?±?3.5 y) and 25 age and sex matched normal subjects (mean age, 6.5?±?2.7 y).

Results

There were no significant statistical differences between mean fractional shortening (FS) and ejection fraction (EF) of left ventricle (LV) of the patients and control group. Children with beta-thalassemia had significantly lower E′ wave velocities measured at the left ventricular septal annulus (8.1?±?3.3 vs. 13?±?2.5, P?<?0.001), lateral margin of the mitral annulus (9.1?±?5.4 vs. 13.3?±?2.5, P?<?0.001) and lateral margin of the tricuspid annulus (9.3?±?3.9 vs. 13.3?±?2.5, P?<?0.001) when compared to the control group. Furthermore children with beta-thalassemia had significantly lower E′/A′ wave ratio at the left ventricular septal annulus (0.76?±?0.34 vs. 1.36?±?0.23), lateral margin of the mitral annulus (0.83?±?0.17 vs. 1.28?±?0.22), and lateral margin of the tricuspid annulus ((0.90?±?0.27 vs. 1.26?±?0.23, (P?<?0.05) when compared to the control group.

Conclusions

This study showed that patients with beta-thalassemia major and normal conventional echo doppler parameters had statistically significant changes detected by pulsed wave tissue doppler imaging.     

Intrapulmonary Shear Stress Enhancement: A New Therapeutic Approach in Pulmonary Arterial Hypertension

Objective

Pulmonary arterial hypertension (PAH) is a dysfunctional endothelium disease with increased pulmonary vascular resistance (PVR) and poor prognosis. Current therapies are still insufficient. Here we propose a new pulsatile device as a more effective tool for PAH management compared with traditional treatments.

Materials and Methods

Twelve piglets (10.3?±?3.8?kg) were given either intrapulmonary pulsatile [P (n?=?6)] or nonpulsatile [NP (n?=?6)] tadalafil treatment. After median sternotomy and heparin injection (250?IU/kg), both groups underwent aorto-pulmonary surgical shunt for 1?h. During a second 1?h period in group P, a catheter prototype, driven by a small ventilator, was introduced into the pulmonary trunk and pulsated intermittently at 110?bpm irrespective of heart rate (90.6?±?10.74 bpm). In group NP, tadalafil was given orally (1?mg/kg).

Results

Hemodynamics and cardiac output (CO) were significantly (p?<?0.05) improved in group P compared with group NP: CO was 0.56?±?0.0.26 versus 0.54?±?0.11 (L/min), respectively. Mean pulmonary artery pressure (PAP) was decreased in group P compared with group NP: PAP was 9.6?±?2.97 versus 32.2?±?5.07, respectively. Vascular resistances (dynes.s.cm^?5/kg) were significantly lower in group P versus group NP: pulmonary resistance was 85?±?42.12 versus 478?±?192.91 and systemic resistance was 298.8?±?172.85 versus 1301?±?615.79, respectively. Using Western blot analysis, endogenous NO synthase expression in PA segments was nonsignificantly (p?>?0.05) greater in group P (0.81?±?0.78) versus (0.62?±?0.35) group NP.

Conclusion

Induced with an appropriate device, intrapulmonary shear stress?Cmediated endothelial function enhancement provides a more effective nearly physiological therapy for PAH.     

Comparative analyses of percutaneous nephrolithotomy versus open surgery in pediatric urinary stone disease

Purpose

The aim of this study is to compare the efficiency and reliability of percutaneous nephrolithotomy (PCNL) and open surgery for pediatric urinary stone disease.

Methods

The retrospective analysis included 116 patients (69 PCNL, 47 open stone surgery). The stone surface area, stone-free rates, hospitalization time, blood transfusion rates, and the D-J implantation rates of patients in each group in whom PCNL and open surgery were performed were analyzed.

Results

The average age of the patients in the PCNL group was 10.01?±?0.51?years, and in the open surgery group 8.55?±?0.68?years. No statistically significant difference was observed between the two groups in average age, stone surface area or stone-free rates. However, hospitalization time (PCNL 2.31?±?0.46?days, open surgery 3.36?±?0.64?days), blood transfusion rate (PCNL 10.1?%, open surgery 42.5?%) and D-J catheter implantation rate (PNL 7.24?%, open surgery 42.5?%) of patients who underwent PCNL were determined to be statistically low.

Conclusion

In light of the results, it is concluded that PCNL supersedes open surgery in terms of the use of advanced instruments and technological developments for modern pediatric surgery.     

Estimation of radiation dose and risk to children undergoing cardiac catheterization for the treatment of a congenital heart disease using Monte Carlo simulations

Background

Children diagnosed with congenital heart disease often undergo cardiac catheterization for their treatment, which involves the use of ionizing radiation and therefore a risk of radiation-induced cancer.

Objective

The purpose of this study was to calculate the effective and equivalent organ doses (H_T) in those children and estimate the risk of exposure-induced death.

Materials and methods

Fifty-three children were divided into three groups: atrial septal defect (ASD), ventricular septal defect (VSD) and patent ductus arteriosus (PDA). In all procedures, the exposure conditions and the dose-area product meters readings were recorded for each individual acquisition. Monte Carlo simulations were run using the PCXMC 2.0 code and mathematical phantoms simulating a child's anatomy. The H_T values to all irradiated organs and the resulting E and risk of exposure-induced death values were calculated.

Results

The average dose-area product values were, respectively, 40?±?12 Gy·cm² for the ASD, 17.5?±?0.7 Gy·cm² for the VSD and 9.5?±?1 Gy·cm² for the PDA group. The average E values were 40?±?12, 22?±?2.5 and 17?±?3.6 mSv for ASD, VSD and PDA groups, respectively. The respective estimated risk of exposure-induced death values per procedure were 0.109, 0.106 and 0.067%.

Conclusion

Cardiac catheterizations in children involve a considerable risk for radiation-induced cancer that has to be further reduced.